US10348244B2 - Method and circuit for exciting a crystal oscillation circuit - Google Patents

Method and circuit for exciting a crystal oscillation circuit Download PDF

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Publication number
US10348244B2
US10348244B2 US15/635,635 US201715635635A US10348244B2 US 10348244 B2 US10348244 B2 US 10348244B2 US 201715635635 A US201715635635 A US 201715635635A US 10348244 B2 US10348244 B2 US 10348244B2
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Prior art keywords
voltage
controlled oscillator
circuit
crystal oscillation
oscillation circuit
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US15/635,635
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US20180337635A1 (en
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Jiazhou Liu
Yunfeng Zhao
Dawei Guo
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Beken Corp
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Beken Corp
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/125—Driving means, e.g. electrodes, coils
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B5/00—Generation of oscillations using amplifier with regenerative feedback from output to input
    • H03B5/30—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element being electromechanical resonator
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B5/00—Generation of oscillations using amplifier with regenerative feedback from output to input
    • H03B5/02—Details
    • H03B5/06—Modifications of generator to ensure starting of oscillations
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B5/00—Generation of oscillations using amplifier with regenerative feedback from output to input
    • H03B5/30—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element being electromechanical resonator
    • H03B5/32—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element being electromechanical resonator being a piezoelectric resonator
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B2200/00—Indexing scheme relating to details of oscillators covered by H03B
    • H03B2200/0002—Types of oscillators
    • H03B2200/0008—Colpitts oscillator
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B2200/00—Indexing scheme relating to details of oscillators covered by H03B
    • H03B2200/0002—Types of oscillators
    • H03B2200/0012—Pierce oscillator
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B2200/00—Indexing scheme relating to details of oscillators covered by H03B
    • H03B2200/003—Circuit elements of oscillators
    • H03B2200/005—Circuit elements of oscillators including measures to switch a capacitor
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B2200/00—Indexing scheme relating to details of oscillators covered by H03B
    • H03B2200/006—Functional aspects of oscillators
    • H03B2200/0074—Locking of an oscillator by injecting an input signal directly into the oscillator
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B2200/00—Indexing scheme relating to details of oscillators covered by H03B
    • H03B2200/006—Functional aspects of oscillators
    • H03B2200/008—Functional aspects of oscillators making use of a reference frequency
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
    • H03B2201/00—Aspects of oscillators relating to varying the frequency of the oscillations
    • H03B2201/02—Varying the frequency of the oscillations by electronic means
    • H03B2201/0275—Varying the frequency of the oscillations by electronic means the means delivering several selected voltages or currents

Definitions

  • the present application relates to a crystal oscillation circuit and more particularly, but not exclusively, to a method and circuit for exciting the crystal oscillation circuit.
  • an additional oscillator may be used as an excitation source.
  • the frequency of the additional oscillator is calibrated to close to the frequency of the crystal oscillator circuit via a calibration circuit. In normal operation, the start-up of the crystal oscillator circuit is relatively fast after being excited by the oscillator.
  • the excitation oscillator is a free-running oscillator
  • the frequency cannot change with the environmental temperature changes after the calibration.
  • temperature change is large, the frequency will deviate from the frequency of the crystal oscillator circuit too much and would not achieve the effect of excitation. Then the excitation oscillator needs to be recalibrated, which will increase the complexity of the circuit design.
  • a method and circuit use a charge circuit with a resistor and a capacitor and a voltage-controlled oscillator to excite a crystal oscillation circuit.
  • the method comprises: charging, with a charging circuit, a voltage-controlled oscillator; providing, with the voltage-controlled oscillator, an exciting signal; blocking, with a direct current blocking capacitor, direct current from the voltage-controlled oscillator to the crystal oscillation circuit; and exciting, with the exciting signal, the crystal oscillation circuit.
  • the circuit comprises: a charging circuit; a voltage-controlled oscillator coupled to the charging circuit and configured to provide an exciting signal to the crystal oscillation circuit; and a direct current blocking capacitor connected between the voltage-controlled oscillator and the crystal oscillation circuit and configured to block direct current from the voltage-controlled oscillator.
  • FIG. 1 is a diagram illustrating an embodiment of a crystal oscillation circuit and an exciting circuit according to an embodiment of the invention.
  • FIG. 2 is a diagram illustrating a function of voltage and frequency for the voltage-controlled oscillator shown in FIG. 1 according to a further embodiment of the invention.
  • FIG. 3 is a diagram illustrating an embodiment of a crystal oscillation circuit and an exciting circuit according to another embodiment of the invention.
  • FIG. 4 is a flowchart of a method for exciting the crystal oscillation circuit shown in FIG. 1 or FIG. 2 according to an embodiment of the invention.
  • FIG. 1 is a diagram illustrating an embodiment of a crystal oscillation circuit 20 and an exciting circuit 10 according to an embodiment of the invention.
  • the crystal oscillation circuit 20 comprises a crystal 180 , an inverter 160 and a buffer 170 .
  • the crystal 180 is connected with the inverter 160 in parallel.
  • the inverter 160 and the crystal 180 are connected to the buffer 170 in series.
  • the crystal oscillation circuit 20 shown in FIG. 1 is an exemplary circuit.
  • the crystal oscillation circuit 20 can be, for example, a Colpitts oscillation circuit, or a Pierce oscillation circuit, etc.
  • the exciting circuit 10 comprises a charging circuit 30 and a voltage-controlled oscillator 140 .
  • the voltage-controlled oscillator 140 is coupled to the charging circuit 30 and configured to provide an exciting signal to the crystal oscillation circuit 20 .
  • the exciting circuit 10 and the crystal oscillation circuit 20 are connected via a direct current blocking capacitor 150 , that is, the direct current blocking capacitor 150 is connected between the voltage-controlled oscillator 140 and the crystal 180 .
  • the direct current blocking capacitor 150 is configured to block direct current from the voltage-controlled oscillator 140 .
  • the charging circuit 30 further comprises a resistor 110 and a capacitor 130 , and wherein the capacitor 130 is connected in parallel to the resistor 110 via a switch 120 .
  • the resistor 110 is 1M ohm and the capacitor 130 is 22 pF and an output voltage of the charging circuit 30 , i.e., the voltage of point B (V B ) is linear voltage increasing from 0.
  • an output clock 190 is connected between the buffer 170 and the voltage-controlled oscillator 140 and configured to control an oscillation time for the voltage-controlled oscillator 140 .
  • the clock 190 can command the voltage-controlled oscillator 140 to be powered down after the crystal oscillates normally.
  • the output clock 190 can count for 2 n cycles, and the value of n can be larger than or equal to zero. For example, 32 (2 5 ) cycles and one cycle is 50 ns.
  • the output clock 190 starts to count, and after the output clock 190 counts for 32 cycles, the voltage-controlled oscillator 140 is powered down.
  • the value of n can be smaller and if the crystal oscillation circuit 20 starts to oscillate slowly, the value of n should be larger.
  • FIG. 2 is a diagram illustrating a function of voltage and frequency for the voltage-controlled oscillator shown in FIG. 1 according to a further embodiment of the invention.
  • the charging circuit 30 starts to charge the voltage-controlled oscillator 140 .
  • the frequency of the voltage-controlled oscillator 140 varies as the voltage of point B (V B , the point B is shown in FIG. 1 ) varies.
  • the natural frequency of the voltage-controlled oscillator 140 is f 0
  • the voltage-controlled gain of the voltage-controlled oscillator 140 is K voc .
  • the initial value of point B is 0, and the initial value of voltage-controlled oscillator 140 is F min , i.e., f 0 .
  • the switch 120 is closed, the value of point B increases linearly and the value of the voltage-controlled oscillator 140 also increases linearly to a maximum value, i.e., F max .
  • the natural frequency of the crystal 180 (F osc ) in the crystal oscillation circuit 20 falls within the range from F min to F max . Since the range is large enough, it can cover F osc regardless of different environmental temperature. Thus, it doesn't need to recalibrate the voltage-controlled oscillator 140 even if environmental temperature changes, and thus will not increase the complexity of the circuit design.
  • FIG. 3 is a diagram illustrating an embodiment of an exciting circuit 10 and a crystal oscillation circuit 40 according to another embodiment of the invention.
  • the exciting circuit 10 is connected to the crystal oscillation circuit 40 via a direct current blocking capacitor 150 . That is, the direct current blocking capacitor 150 is connected between the voltage-controlled oscillator 140 in the exciting circuit 10 and the crystal 180 in the crystal oscillation circuit 40 .
  • the crystal oscillation circuit 40 is a Colpitts oscillation circuit.
  • the basic structure of the Colpitts oscillation circuit 40 is similar to the structure of the crystal oscillation circuit 20 shown in FIG. 1 . A difference between these two structures is the grounding mode.
  • the grounding mode of the crystal oscillation circuit 40 does not affect the operating principle of the crystal oscillation circuit 40 , that is, the Colpitts oscillation circuit 40 works similarly to the crystal oscillation circuit 20 shown in FIG. 1 . Then the voltage-controlled oscillator 140 in the exciting circuit 10 can excite the crystal 180 in the crystal oscillation circuit 40 as described with respect to FIG. 1 and FIG. 2 .
  • the output clock 190 in the crystal oscillation circuit 40 is connected between the buffer 170 in the crystal oscillation circuit 40 and the voltage-controlled oscillator 140 and configured to control an oscillation time for the voltage-controlled oscillator 140 .
  • the clock 190 can command the voltage-controlled oscillator 140 to be powered down after the crystal oscillates normally.
  • the output clock 190 can count for 2 n cycles, and the value of n can be larger than or equal to zero. For example, 32 (2 5 ) cycles and one cycle is 50 ns.
  • the output clock 190 starts to count, and after the output clock 190 counts for 32 cycles, the voltage-controlled oscillator 140 is powered down.
  • the value of n can be smaller and if the crystal oscillation circuit 40 starts to oscillate slowly, the value of n should be larger.
  • the charging circuit 30 in the exciting circuit 10 starts to charge the voltage-controlled oscillator 140 .
  • the frequency of the voltage-controlled oscillator 140 varies as the voltage of point B (V B , the point B is shown in FIG. 3 ) varies.
  • the natural frequency of the voltage-controlled oscillator 140 is f 0
  • the voltage-controlled gain of the voltage-controlled oscillator 140 is K voc .
  • the initial value of point B is 0, and the initial value of voltage-controlled oscillator 140 is F min , i.e., f 0 . Then, the switch 120 is closed, the value of point B increases linearly and the value of the voltage-controlled oscillator 140 also increases linearly to a maximum value, i.e., F max .
  • F max the maximum value
  • the natural frequency of the crystal 180 (F osc ) in the crystal oscillation circuit 40 falls within the range from F min to F max . Since the range is large enough, it can cover F osc regardless of different environmental temperature. Thus, it doesn't need to recalibrate the voltage-controlled oscillator 140 even if environmental temperature changes, and thus will not increase the complexity of the circuit design.
  • FIG. 4 is a flowchart of a method 400 for exciting the crystal oscillation circuit shown in FIG. 1 or FIG. 3 according to an embodiment of the invention.
  • the method 400 for exciting a crystal oscillation circuit comprises: charging, in block 410 , with a charging circuit, a voltage-controlled oscillator; providing, in block 420 , with the voltage-controlled oscillator, an exciting signal; blocking, in block 430 , with a direct current blocking capacitor, direct current from the voltage-controlled oscillator to the crystal oscillation circuit; exciting, in block 440 , with the exciting signal, the crystal oscillation circuit.
  • the charging circuit further comprise a resistor and a capacitor, and wherein the capacitor is connected in parallel to the resistor via a switch.
  • the resistor is 1M ohm and the capacitor C2 is 22 pF and an output voltage of the charging circuit is linear voltage increasing from 0.
  • the frequency of the voltage-controlled oscillator varies with the output voltage of the charging circuit and an oscillation frequency of the crystal oscillation circuit falls within a frequency range from a minimum frequency of the voltage controlled oscillator (F min ) to a maximum frequency of the voltage controlled oscillator (F max ).
  • F min a minimum frequency of the voltage controlled oscillator
  • F max a maximum frequency of the voltage controlled oscillator
  • the natural frequency of the voltage-controlled oscillator is f 0
  • the voltage-controlled gain of the voltage-controlled oscillator is K voc .
  • the initial value of point B (see the point B in FIG.
  • the initial value of voltage-controlled oscillator is F min , i.e., f 0 .
  • the value of the voltage-controlled oscillator also increases linearly to a maximum value, i.e., F max .
  • the natural frequency of the crystal (F osc ) in the crystal oscillation circuit falls within the range from F min to F max Since the range is large enough, it can cover F osc regardless of different environmental temperature. Thus, it doesn't need to recalibrate the voltage-controlled oscillator even if environmental temperature changes, and thus will not increase the complexity of the circuit design.
  • the crystal oscillation circuit further comprises an output clock connected between the buffer and the voltage-controlled oscillator and configured to control an oscillation time for the voltage-controlled oscillator.
  • the clock can command the voltage-controlled oscillator to be powered down after the crystal oscillates normally.
  • the output clock can count for 2 n cycles, for example, 32 (2 5 ) cycles and one cycle is 50 ns. After the crystal starts to oscillate, the output clock starts to count, and after the output clock counts for 32 cycles, the voltage-controlled oscillator is powered down.

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  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Oscillators With Electromechanical Resonators (AREA)
US15/635,635 2017-05-16 2017-06-28 Method and circuit for exciting a crystal oscillation circuit Active 2037-12-02 US10348244B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
CN201710344440.2 2017-05-16
CN201710344440.2A CN108880504B (zh) 2017-05-16 2017-05-16 用于激励晶体振荡电路的方法以及电路
CN201710344440 2017-05-16

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CN113193837B (zh) * 2021-05-20 2023-01-24 北京奕斯伟计算技术股份有限公司 启动电路、晶体振荡器和通信芯片

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4722070A (en) * 1982-12-21 1988-01-26 Texas Instruments Incorporated Multiple oscillation switching circuit
US5694092A (en) * 1995-07-13 1997-12-02 Nec Corporation Voltage-controlled oscillator including first and second varactors having differing rates of change in capacitance value
US6366175B2 (en) * 1999-12-06 2002-04-02 Seiko Epson Corporation Temperature compensated oscillator, method of controlling temperature compensated oscillator, and wireless communication device
US9197157B1 (en) * 2014-09-08 2015-11-24 Google Inc. One-pin crystal oscillator driven through a general purpose input/output device

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5703538A (en) * 1996-09-18 1997-12-30 Hughes Electronics Radar exciter local oscillator phase lock acquisition control circuit
JP2000196356A (ja) * 1998-12-28 2000-07-14 Nippon Dempa Kogyo Co Ltd 電圧制御型の水晶発振器
DE60126862T2 (de) * 2000-05-02 2007-10-31 Thomson Licensing Phasenregelung für Oszillatoren
CN100581056C (zh) * 2006-11-10 2010-01-13 天时电子股份有限公司 不受温度变化及供应电压变化影响的稳定振荡器
JP5092770B2 (ja) * 2008-01-29 2012-12-05 富士通セミコンダクター株式会社 位相ロックループ回路及び遅延ロックループ回路
CN101651456B (zh) * 2008-08-12 2012-03-21 博通集成电路（上海）有限公司 时钟信号恢复的电路
CN101729024A (zh) * 2008-10-28 2010-06-09 博通集成电路（上海）有限公司 混合信号的电路和方法
CN101951259A (zh) * 2010-08-26 2011-01-19 上海南麟电子有限公司 锁相环及其自动频率校准电路、锁相环自调谐锁定方法
CN103916150B (zh) * 2013-01-07 2016-09-14 深圳市锐迪芯电子有限公司 一种无晶体振荡器的无线接收器

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4722070A (en) * 1982-12-21 1988-01-26 Texas Instruments Incorporated Multiple oscillation switching circuit
US5694092A (en) * 1995-07-13 1997-12-02 Nec Corporation Voltage-controlled oscillator including first and second varactors having differing rates of change in capacitance value
US6366175B2 (en) * 1999-12-06 2002-04-02 Seiko Epson Corporation Temperature compensated oscillator, method of controlling temperature compensated oscillator, and wireless communication device
US9197157B1 (en) * 2014-09-08 2015-11-24 Google Inc. One-pin crystal oscillator driven through a general purpose input/output device

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CN108880504A (zh) 2018-11-23
CN108880504B (zh) 2021-10-08
US20180337635A1 (en) 2018-11-22

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